Sun, 25 Feb 2018 12:55:07 +0000 paulson merged
Sun, 25 Feb 2018 12:54:55 +0000 paulson new material on matrices, etc., and consolidating duplicate results about of_nat
Sun, 25 Feb 2018 12:59:08 +0100 wenzelm notation for dummy sort;
(0) -30000 -10000 -3000 -1000 -300 -100 -30 -10 -3 +3 +10 +30 +100 +300 +1000 +3000 tip